1. Field of the Invention
The present invention relates to a light source device and a liquid crystal display (LCD) device including the light source device.
2. Discussion of the Background
A liquid crystal display (LCD) device includes a liquid crystal display panel and a backlight unit. The liquid crystal display panel includes a thin film transistor (TFT) substrate, a counter substrate, and a liquid crystal layer disposed between the TFT substrate and the counter substrate. As the LCD panel does not emit light itself, it receives light from a backlight unit that is disposed behind the TFT substrate. The light transmittance of the backlight unit may be adjusted according to the arrangement of liquid crystals.
A point light source, such as a light emitting diode, has become a more popular light source for a backlight unit than a line light source, such as a lamp.
The light emitting diode may be a chip on board (COB) type in which a light emitting diode chip is mounted in a substrate. The mounted light emitting diode chip is encapsulated by an encapsulant, which includes resin or silicon, to adjust the emission angle. The encapsulant protects the light emitting diode chip.
As the COB type of light emitting diode does not require a packaging process, production costs may be reduced as compared to a package type in which the light emitting diode chip must be packaged and mounted in a substrate.
If the backlight unit employs a light emitting diode, a plurality of light emitting diodes may be used to emit different colors of light. The light from the light emitting diodes may be mixed and may become white light to be supplied to the LCD panel.
However, if the different colors of light are not sufficiently mixed, color shading occurs in the LCD device and light uniformity is very low. Also, as light efficiency decreases, the brightness of light supplied to the LCD device becomes unsatisfactory.